Environnement, Risques & Santé
MENUEvaluating water potability in a populated zone of the Senegalese Sahel: Niakhar Volume 6, issue 5, Septembre-Octobre 2007
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- Key words: Africa, fluoride poisoning, fluorine, fresh water, salinity, sodium, sodium chloride, water pollution
- DOI : 10.1684/ers.2007.0105
- Page(s) : 373-81
- Published in: 2007
Chemical and microbiological analyses of deep and surface water were conducted in Niakhar, a densely populated zone 200 km 2 in area in the Senegalese Sahel, 150 km east of Dakar, the capital. We identified approximately 500 water points there randomly selected 71 for chemical analyses and 40 for bacteriological analyses. A very strong mineralization of deep as well as surface water was observed. In one third of the water points sampled, fluorine concentrations, and in two thirds, sodium chloride concentrations exceeded World Health Organization and European Union guidelines. Sodium, potassium, calcium and manganese concentrations also exceeded recommended levels in most water sources. These levels appeared to correspond to several specific water distribution networks. Contamination by E. coli was low, but contamination by faecal streptococcus was very high in most water points, including the terminal hydrants, could be due to distribution and storage conditions that favor bacterial multiplication more than to intense pollution of faecal origin